Data storage devices (DSD) store data and include a mechanical portion, or head-disk assembly (HDA) and an electronics portion, or printed circuit board wiring assembly (PWA), controlling functions of the HDA while providing a communication interface between the HDA and a host being serviced by the DSD. The HDA has a disk, with data recorded on a recording surface, rotated at a constant speed by a motor assembly, the data is accessed by a read/write head of an actuator assembly the position of which is controlled by a closed loop servo system. The data storage device market continues to place pressure on the industry for DSD's with higher rates of data throughput.
DSD standards have recently been revised to change the physical sectors on the drives from 512 bytes to 1024 bytes (or “1K”). While the Advanced Technology Attachment (“ATA”) standard allows the local block address (“LBA”) to be changed to conform to the physical sector size, changing the LBA from 512 bytes is not presently compatible with the basic input/output system (“BIOS”), operating system software, applications, host interface, drive interface, and hardware. These legacy operating systems, applications, and hardware still transmit and request data in 512 byte blocks. Some of the hardware is actually “hard wired” to read and write in 512 bytes and cannot be changed via a firmware update.
Even though the physical sector size on a hard disk drive may be 1K, it will still have to manage data transfer requests, file allocation tables (“FAT”), and drive partitioning based upon 512 byte formats. For optimal performance, data transfers should start on even LBAs and end on odd LBAs as even LBAs are aligned with the beginning of each 1K physical sector. This means that for operating systems and hardware limited to 512 byte functionality, the beginning of each odd LBA is unaligned with a physical sector and must be located using a read command before the remaining data can be written. This degrades the DSD writing time and thus the performance of the DSD in time-critical applications.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.